A Labour MP has called on the Prime Minister to renew efforts to bring to justice those responsible for the 1974 Birmingham pub bombings which killed 21 people.
Khalid Mahmood (Birmingham, Perry Barr) asked what action David Cameron intended to take on the 40th anniversary of the attacks.
Mr Mahmood told the Commons he attended a service at the weekend with families of those who lost loved ones, adding: "After a 40-year-long wait there is still no action to bring to justice the perpetrators."
Mr Cameron replied: "First of all, our sympathies and condolences should still go to those people who lost their relatives 40 years ago.<
"When you lose a relative that stays with you. The grief and the pain stays with you forever.
"I think it is important that we continue to work to try and make sure that we address all the issues that happened in the past and find those that are responsible and try to help people come to terms with what has happened.
"That needs to happen in Northern Ireland as well as on the mainland."
Twenty-one people lost their lives in the bombings on November 21, which also left more than 180 injured. The two blasts - at the Mulberry Bush and Tavern in the Town pubs - happened when the bars were packed with teenage drinkers.
Police had tried to evacuate the premises after the Birmingham Post newspaper received a telephone warning the attacks were imminent, but failed to do so in time.
The so-called Birmingham Six were found guilty in 1975, but released after 16 years in prison when their convictions were overturned in 1991. The real perpetrators have never been prosecuted.
A memorial service has been held at Birmingham Cathedral to remember the victims of the Birmingham pub bombings 40 years ago tonight.Read the full story ›
Over the next hour on this night 40 years ago, lives would be wrecked & families ripped apart, after bombs were planted by the IRA in two pubs in Birmingham city centre.
A warning call would be made to the Birmingham Mail at 8.11pm, saying bombs would go off under the Rotunda and on New Street.
At 8.17pm a device exploded at the Mulberry Bush. Ten minutes later, a second blast destroyed basement bar The Tavern in the Town.
A total of 21 people would lose their lives in the terrorist attacks. In half an hour's time 182 more would be maimed and injured.
One of the survivors on this night in 1974 was Les Robinson. Watch his incredible story above.
Les Robinson was 22 when a bomb devastated the Tavern in the Town pub in Birmingham city centre on this night exactly 40 years ago.
He was meeting around 15 to 18 friends in the pub that night. Many hadn't arrived when the bomb exploded, but seven of his friends were injured.
None of his friends lost their lives, but Les says friendships did fall apart in the months after the terrorist attacks, but for reasons you'd never expect, as he explained to ITV News Central reporter Chris Halpin.
Mainland Britain lived in the shadow of terrorism during the 1970s, with bombings commonplace, but the Birmingham bombs were to be the deadliest of the decade.
Attitudes towards the city's Irish community during the Northern Ireland Troubles was tense before that night. Now hostility became hatred.
Bomb survivor Les Robinson, who was stood just ten feet away from the blast in the Tavern in the Town when a device exploded at 8.27pm on this night in 1974.
Here Les explains how the blast divided his family, with his Irish uncle too ashamed to visit him after he was injured.
Forty years since the city centre pub bombings which rocked Birmingham, not all those left behind want the truth about what happened.Read the full story ›
Les Robinson was 22-years-old went he was badly injured in the bomb blast in the Tavern in the Town on this night 40 years ago.
Devices planted in the Mulberry Bush underneath the Rotunda building, and in the Tavern in the Town on New Street, exploded at 8.17pm and 8.27pm, killing 21 people and injuring 182 others.
Les describes to ITV News Central reporter Chris Halpin his struggle with going into a pub for the first time after surviving the terrorist attack.
Les Robinson was one of the scores injured when a bomb ripped through The Tavern in the Town pub in Birmingham city centre 40 years ago tonight.
Twenty-one people died and 182 were injured when two devices planted by the IRA exploded in the Mulberry Busy and Tavern in the Town on November 21st 1974.
No one has ever been brought to justice for the bombings, which remains one of Britain's largest unsolved mass murders.
Despite this, Les told ITV News Central reporter Chris Halpin, he does have closure on the events that night.
A concert was held in Birmingham last night on the 40th anniversary of the pub bombings. It was organised by Julie Hambleton who lost her sister in the attacks. 21 people were killed.
A memorial evensong service for the victims of the Birmingham pub bombings will be held at the city's St Philip's Cathedral this evening to mark the 40th anniversary of the tragedy.
The bombings claimed the lives of 21 people and injured 182.
The evensong will be attended by family and friends of those who were killed or injured, and will then continue in Cathedral Square.
A minute's silence will be held at 8.26pm to mark the moment the first bomb exploded.
The service will be an opportunity to reflect on a deeply difficult time.
At this time our thoughts will be with the families of those that suffered not only with the loss of loved ones, but also those who received injuries.
I hope the service will bring strength and depth to all.